Update LLVM to r86025.

1 files changed, 176 insertions, 0 deletions

diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.h b/lib/CodeGen/AggressiveAntiDepBreaker.h
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+//=- llvm/CodeGen/AggressiveAntiDepBreaker.h - Anti-Dep Support -*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the AggressiveAntiDepBreaker class, which
+// implements register anti-dependence breaking during post-RA
+// scheduling. It attempts to break all anti-dependencies within a
+// block.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_AGGRESSIVEANTIDEPBREAKER_H
+#define LLVM_CODEGEN_AGGRESSIVEANTIDEPBREAKER_H
+
+#include "AntiDepBreaker.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/ScheduleDAG.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/SmallSet.h"
+
+namespace llvm {
+  /// Class AggressiveAntiDepState 
+  /// Contains all the state necessary for anti-dep breaking. We place
+  /// into a separate class so be can conveniently save/restore it to
+  /// enable multi-pass anti-dep breaking.
+  class AggressiveAntiDepState {
+  public:
+    /// RegisterReference - Information about a register reference
+    /// within a liverange
+    typedef struct {
+      /// Operand - The registers operand
+      MachineOperand *Operand;
+      /// RC - The register class
+      const TargetRegisterClass *RC;
+    } RegisterReference;
+
+  private:
+    /// GroupNodes - Implements a disjoint-union data structure to
+    /// form register groups. A node is represented by an index into
+    /// the vector. A node can "point to" itself to indicate that it
+    /// is the parent of a group, or point to another node to indicate
+    /// that it is a member of the same group as that node.
+    std::vector<unsigned> GroupNodes;
+  
+    /// GroupNodeIndices - For each register, the index of the GroupNode
+    /// currently representing the group that the register belongs to.
+    /// Register 0 is always represented by the 0 group, a group
+    /// composed of registers that are not eligible for anti-aliasing.
+    unsigned GroupNodeIndices[TargetRegisterInfo::FirstVirtualRegister];
+  
+    /// RegRefs - Map registers to all their references within a live range.
+    std::multimap<unsigned, RegisterReference> RegRefs;
+  
+    /// KillIndices - The index of the most recent kill (proceding bottom-up),
+    /// or ~0u if the register is not live.
+    unsigned KillIndices[TargetRegisterInfo::FirstVirtualRegister];
+  
+    /// DefIndices - The index of the most recent complete def (proceding bottom
+    /// up), or ~0u if the register is live.
+    unsigned DefIndices[TargetRegisterInfo::FirstVirtualRegister];
+
+  public:
+    AggressiveAntiDepState(MachineBasicBlock *BB);
+    
+    /// GetKillIndices - Return the kill indices.
+    unsigned *GetKillIndices() { return KillIndices; }
+
+    /// GetDefIndices - Return the define indices.
+    unsigned *GetDefIndices() { return DefIndices; }
+
+    /// GetRegRefs - Return the RegRefs map.
+    std::multimap<unsigned, RegisterReference>& GetRegRefs() { return RegRefs; }
+
+    // GetGroup - Get the group for a register. The returned value is
+    // the index of the GroupNode representing the group.
+    unsigned GetGroup(unsigned Reg);
+    
+    // GetGroupRegs - Return a vector of the registers belonging to a
+    // group.
+    void GetGroupRegs(unsigned Group, std::vector<unsigned> &Regs);
+
+    // UnionGroups - Union Reg1's and Reg2's groups to form a new
+    // group. Return the index of the GroupNode representing the
+    // group.
+    unsigned UnionGroups(unsigned Reg1, unsigned Reg2);
+
+    // LeaveGroup - Remove a register from its current group and place
+    // it alone in its own group. Return the index of the GroupNode
+    // representing the registers new group.
+    unsigned LeaveGroup(unsigned Reg);
+
+    /// IsLive - Return true if Reg is live
+    bool IsLive(unsigned Reg);
+  };
+
+
+  /// Class AggressiveAntiDepBreaker 
+  class AggressiveAntiDepBreaker : public AntiDepBreaker {
+    MachineFunction& MF;
+    MachineRegisterInfo &MRI;
+    const TargetRegisterInfo *TRI;
+
+    /// AllocatableSet - The set of allocatable registers.
+    /// We'll be ignoring anti-dependencies on non-allocatable registers,
+    /// because they may not be safe to break.
+    const BitVector AllocatableSet;
+
+    /// State - The state used to identify and rename anti-dependence
+    /// registers.
+    AggressiveAntiDepState *State;
+
+    /// SavedState - The state for the start of an anti-dep
+    /// region. Used to restore the state at the beginning of each
+    /// pass
+    AggressiveAntiDepState *SavedState;
+
+  public:
+    AggressiveAntiDepBreaker(MachineFunction& MFi);
+    ~AggressiveAntiDepBreaker();
+    
+    /// GetMaxTrials - As anti-dependencies are broken, additional
+    /// dependencies may be exposed, so multiple passes are required.
+    unsigned GetMaxTrials();
+
+    /// NeedCandidates - Candidates required.
+    bool NeedCandidates() { return true; }
+
+    /// Start - Initialize anti-dep breaking for a new basic block.
+    void StartBlock(MachineBasicBlock *BB);
+
+    /// BreakAntiDependencies - Identifiy anti-dependencies along the critical path
+    /// of the ScheduleDAG and break them by renaming registers.
+    ///
+    unsigned BreakAntiDependencies(std::vector<SUnit>& SUnits,
+                                   CandidateMap& Candidates,
+                                   MachineBasicBlock::iterator& Begin,
+                                   MachineBasicBlock::iterator& End,
+                                   unsigned InsertPosIndex);
+
+    /// Observe - Update liveness information to account for the current
+    /// instruction, which will not be scheduled.
+    ///
+    void Observe(MachineInstr *MI, unsigned Count, unsigned InsertPosIndex);
+
+    /// Finish - Finish anti-dep breaking for a basic block.
+    void FinishBlock();
+
+  private:
+    /// IsImplicitDefUse - Return true if MO represents a register
+    /// that is both implicitly used and defined in MI
+    bool IsImplicitDefUse(MachineInstr *MI, MachineOperand& MO);
+    
+    /// GetPassthruRegs - If MI implicitly def/uses a register, then
+    /// return that register and all subregisters.
+    void GetPassthruRegs(MachineInstr *MI, std::set<unsigned>& PassthruRegs);
+
+    void HandleLastUse(unsigned Reg, unsigned KillIdx, const char *tag);
+    void PrescanInstruction(MachineInstr *MI, unsigned Count,
+                            std::set<unsigned>& PassthruRegs);
+    void ScanInstruction(MachineInstr *MI, unsigned Count);
+    BitVector GetRenameRegisters(unsigned Reg);
+    bool FindSuitableFreeRegisters(unsigned AntiDepGroupIndex,
+                                   std::map<unsigned, unsigned> &RenameMap);
+  };
+}
+
+#endif